From: Jonathan Wakely <jwakely@redhat.com>
Date: Tue, 18 Jun 2024 19:57:24 +0000 (+0100)
Subject: libstdc++: Add conditional noexcept to std::pair default ctor
X-Git-Tag: basepoints/gcc-16~8103
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9651d6005f9c1ac60aecf7b36d6c0bd1ead8a63b;p=thirdparty%2Fgcc.git

libstdc++: Add conditional noexcept to std::pair default ctor

Most of std::pair constructors implemented using C++20 concepts have a
conditional noexcept-specifier, but the default constructor doesn't.
This fixes that.

libstdc++-v3/ChangeLog:

	* include/bits/stl_pair.h [__cpp_lib_concepts] (pair()): Add
	conditional noexcept.
---

diff --git a/libstdc++-v3/include/bits/stl_pair.h b/libstdc++-v3/include/bits/stl_pair.h
index 0c1e5719a1a..0d60eaba194 100644
--- a/libstdc++-v3/include/bits/stl_pair.h
+++ b/libstdc++-v3/include/bits/stl_pair.h
@@ -344,6 +344,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       explicit(__not_<__and_<__is_implicitly_default_constructible<_T1>,
 			     __is_implicitly_default_constructible<_T2>>>())
       pair()
+      noexcept(is_nothrow_default_constructible_v<_T1>
+		&& is_nothrow_default_constructible_v<_T2>)
       requires is_default_constructible_v<_T1>
 	       && is_default_constructible_v<_T2>
       : first(), second()